I've been getting too much wort into my boil kettle, and I think it has to do with the connection between volume and temperature in the schedule. I'm pretty sure this is not a BTPro problem -- I think it's something I don't get.

Preface -- I batch sparge and I have my schedule set up just like the recommended method for that; I also have calibrated my equipment according to the directions.

I've been playing with this problem for a couple of hours this evening, and I think I've found a solution, but it seems weird to me.

Here are my two questions:

1. Right before my separation step, in my mash-out rest, the schedule says I've got 3.62G available. Yet, in the editor for my separation step, if I enter a residual of 0 in the first runnings step, I get only 3.46G. If I try to enter 3.62G, I end up with a negative residual. Then, things get weirder, b/c in the Schedule list, it shows me as having collected 3.61G in that step. I'm guessing this must have something to do with the temp factor and the difference in volume between one temp and another?

And that brings us to question #2:

2. I want to get 1/2 my volume in each step of my lauter (first runnings, then one sparge). Because of the change in volume due to temperature, the only way I've found to do that is to set up all my steps for 212

When I change the temps in the edit window all to 211.6 (the max the program allows me due to my altitude), the Total Runoff displayed in the edit window matches the last Collected displayed in the Schedule window If I reduce the temps in the edit window, neither of these volumes change. If I understand, this is different than how the program is acting for you. Is this true?

The Kettle Volume is typed in separately and is not dependent on the runnoff volumes, if you weren't already aware of that. So make your Total Runoff equal the volume you've decided to enter into your Kettle Volume and it should work, if the program works the same for you as for me. If not, what version are you using?

When I change the temps in the edit window all to 211.6 (the max the program allows me due to my altitude), the Total Runoff displayed in the edit window matches the last Collected displayed in the Schedule window If I reduce the temps in the edit window, neither of these volumes change. If I understand, this is different than how the program is acting for you. Is this true?

I'm a little confused by the behavior you describe here -- do I understand correctly that if you change the temps in the edit window all to be 212, the total runoff amount changes, but that if you then change them back to what you want, the total runoff does NOT change? Maybe I'm misunderstanding? If I change the temp of my first runnings in the edit window, the total runoff value does not change. If I change the temp of my sparge step, the total runoff volume DOES change. I suspect this is because the first runnings step has a value of 0.0 for volume in the edit window (because I'm not adding any water for that step). Thus, if I change all temps in the edit window to 212, the total runoff changes.

In any case, total runoff in the edit window does always match the last collected amount in the Schedule. What does not match is the intermediate step, the first runnings step. If you check out the screenshot above, you'll see that BTPro says I have 3.51G available after mashout, and that I collect 3.51G from my first runnings -- all good. In the edit window, however, it claims that with a residual of zero and volume of zero for first runnings, I collect 3.44G for that same step.

Now, if I change the target temp of my mash-out to 212 -- which turns red, since I would need water at 383

Are you sure your evaporation losses are set correctly? Rather than fudge with the temperatures so you can hit the volumes you are used to, adjust the evaporation rate up or down and see how that works with the actual temps. It's very possible that you're evaporating less (or more) than you think. I had that problem on my spreadsheet (before starting to use BeerTools Pro), and once a local brewer helped me figure that out, everything turned out fine.

just-cj wrote:Are you sure your evaporation losses are set correctly? Rather than fudge with the temperatures so you can hit the volumes you are used to, adjust the evaporation rate up or down and see how that works with the actual temps. It's very possible that you're evaporating less (or more) than you think. I had that problem on my spreadsheet (before starting to use BeerTools Pro), and once a local brewer helped me figure that out, everything turned out fine.

I'm pretty sure my evap rates are fine. In fact, I'm more sure of that than I might be, since I've had to extrapolate from them on the fly to fix this excess wort problem. Anyway, the issue has been pre-boil, not post.

I'm happy to say that I'm mid-boil on my 2nd batch of the day, and using my "set everything to 212 then work backwards" system appears to be working. My pre-boil volumes were just what I wanted today. I still think I'm kind of gaming the system to make it work, but it is at least working this way.

I wonder if it would be possible to choose to express water volumes in terms of weight (@ 8.34 #/G)? That's how I measure my water, as I find it more accurate than going by volume, since volume changes with temperature.

I do get the behavior you describe.
I just didn't see it's effect on total volume because the effect was so small (4 oz.).

I see what you mean about it being nice if the volumes all agreed, but I think you see the problem getting all the numbers to add up because of the temperature changes. If you just focus on the total runoff and don't worry about getting the volumes perfectly equal, you'll be fine. If you're setting the volumes equal based on their volume at 212

Well.... maybe I've just had too much IPA, but I'm not inclined to think about it any further, at the moment, anyway. I brewed two batches today with my new system and both were spot on in terms of pre-boil volume (or at least close enough to where I couldn't see the error). I still don't like having to set everything to 212 and then change it, but at least it works. Perhaps I'll revisit the topic when I'm more sober and see if I can make heads or tails of what the problem was earlier.